Sébastien Lecornu, France’s fourth prime minister in a year, faces big challenges like a ballooning deficit and unrest.

iStock/LuevanosLast year, for the first time in history, America's richest billionaires paid a lower effective tax rate than the working class, according to a new study. The analysis found that the wealthiest 400 families in the country paid an average tax rate of 23 percent in 2018, while the bottom half of households paid an average tax rate of 24.2 percent. In 1960, the top 400 families had an average tax rate of 56 percent, according to a report from the Washington Post. Meanwhile, the working class's tax rate has remained relatively stable, the report said. The economists write that they decided to examine the top 400 families because they currently hold more wealth than the bottom 60 percent of households.